In individual section glassware forming machines, mold charges or gobs of molten glass are fed by a gob distributor along troughs to the machine sections in sequence, and then by deflectors at each machine section into the blank molds at that section. The deflectors have an arcuate contour to convert the downwardly angled motion along the troughs to vertical motion into the blank molds. U.S. Pat. No. 4,772,306 teaches that the centerline of the deflector lies along a spiral curve in which the radius varies as a function of angle. Thus, in FIG. 8 of the present application, the radius of the centerline of the deflector curve varies according to the equation r=C/θP, where θ is angle from the deflector exit end, C is a constant that is determined at a selected (r,θ) coordinate pair, and P is an exponent that controls the shape of the curve. The deflector curve has a minimum radius at the entrance end from the associated trough, and a maximum radius at the exit end above the associated blank mold. The height of the deflector is controlled by the layout of the machine, and is specified as the intersection height a, which is the vertical distance above the deflector exit to a point that intersects the trough centerline.
A major concern in the design of gob deflectors is the normal or radial force exerted by the deflector on the gob due to centrifugal acceleration during travel of the glass gob along the deflector. A positive normal force throughout travel along the deflector is necessary to maintain control of the gob, and to control loading of the gob into the blank mold. However, excessive normal force increases heat transfer from the gob to the deflector, increases friction between the gob and the surface of the deflector, causes greater elongation of the gob, and cools the gob on the side in contact with the deflector, which undesirably can lead to distortion of the blow molded glass container. Furthermore, a high normal force at the exit end of the deflector would allow the gob to continue to travel outward as the gob leaves the exit end of the deflector, rather than vertically downwardly into the associated blank mold. A general object of the present invention is to provide a gob deflector that addresses these areas of concern.